Fabrication of Au thin film gratings by pulsed laser interference

We report that one-dimensional (1D) and two-dimensional (2D) metal thin film gratings can be directly fabricated by interfering Nd-YAG pulsed laser beams (wavelength = 1064 nm, pulse width = 6 ns) incident from the backside of glass substrate. This process utilizes a laser-induced thermo-elastic force which plays a role to detach the film from the substrate. Micro-scale Au transmission gratings with a minimum feature size of 1 μm could be generated by interference-driven periodic detachment. The fabrication of tube-structured patterns as well as stripes was also possible by adjusting the pulse power and this is explained with the effect of film cohesion.